hippocampus

American  

[hip-uh-kam-puhs] / ˌhɪp əˈkæm pəs /

noun

plural

hippocampi

1. Classical Mythology. a fish-tailed horse of the sea that was ridden by the sea gods.

2. Anatomy. an enfolding of cerebral cortex into the lateral fissure of a cerebral hemisphere, having a major role in learning, emotion, and memory, and named for the seahorse shape of its cross section.

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hippocampus British  

/ ˌhɪpəʊˈkæmpəs /

noun

1. a mythological sea creature with the forelegs of a horse and the tail of a fish

2. any marine teleost fish of the genus Hippocampus, having a horselike head See sea horse

3. an area of cerebral cortex that forms a ridge in the floor of the lateral ventricle of the brain, which in cross section has the shape of a sea horse. It functions as part of the limbic system

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hippocampus Scientific  

/ hĭp′ə-kăm′pəs /

plural

hippocampi

1. A convoluted, seahorse-shaped structure in the cerebral cortex of the temporal lobe of the brain, composed of two gyri with white matter above gray matter. It forms part of the limbic system and is involved in the processing of emotions and memory.

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Other Word Forms

• hippocampal adjective

Etymology

Origin of hippocampus

First recorded in 1575–80; from Latin hippocampus, hippocampos, from Greek hippókampos, equivalent to hippo- hippo- + kámpos “sea monster”

Example Sentences

At the same time, they had fewer connections between neurons in the hippocampus and performed worse on cognitive tests.

From Science Daily • Apr. 5, 2026

It activates or suppresses genes within the circuit connecting the brain's reward center and the hippocampus, which serves as the brain's memory hub.

From Science Daily • Mar. 6, 2026

Researchers observed a gradual pattern across regions, with the hippocampus showing the largest effects and smaller but still significant associations appearing across much of the brain.

From Science Daily • Jan. 14, 2026

While the hippocampus remains especially sensitive, it functions as part of a broader system rather than acting alone.

From Science Daily • Jan. 14, 2026

His hippocampus was treating him to 360° aerials and backward ollies, and Tyson was laughing so hysterically, the sound echoed up the side of the ship.

From "The Sea of Monsters" by Rick Riordan